Physicians have long recognized that a disproportionate number of individuals with mental illnesses smoke. About 41% of all individuals who’ve had a mental illness in the past month smoke compared with 22.5% of those who have never had a mental illness (Lasser K et al. JAMA. 2000;284:2606-2610). Some estimates of smoking among the mentally ill are even higher and many studies show individuals with mental illnesses are less likely to quit. Now, scientists are beginning to understand the underlying causes of this discrepancy and their findings are pointing to potential new treatments for both mental illness and smoking cessation.